413 research outputs found
On a functional satisfying a weak Palais-Smale condition
In this paper we study a quasilinear elliptic problem whose functional
satisfies a weak version of the well known Palais-Smale condition. An existence
result is proved under general assumptions on the nonlinearities.Comment: 18 page
Ground state solutions to the nonlinear Schrodinger-Maxwell equations
We prove the existence of ground state solutions for the nonlinear
Schrodinger-Maxwell equations.Comment: 27 page
Wavelength calibration of the JWST-MIRI medium resolution spectrometer
We present the wavelength and spectral resolution characterisation of the
Integral Field Unit (IFU) Medium Resolution Spectrometer for the Mid-InfraRed
Instrument (MIRI), to fly onboard the James Webb Space Telescope in 2014. We
use data collected using the Verification Model of the instrument and develop
an empirical method to calibrate properties such as wavelength range and
resolving power in a portion of the spectrometer's full spectral range (5-28
microns). We test our results against optical models to verify the system
requirements and combine them with a study of the fringing pattern in the
instrument's detector to provide a more accurate calibration. We show that
MIRI's IFU spectrometer will be able to produce spectra with a resolving power
above R=2800 in the wavelength range 6.46-7.70 microns, and that the unresolved
spectral lines are well fitted by a Gaussian profile.Comment: 12 pages, submitted to SPIE Proceedings vol. 7731, Space Telescopes
and Instrumentation 2010: Optical, Infrared, and Millimeter Wav
Disk galaxies with broken luminosity profiles from cosmological simulations
We present SPH cosmological simulations of the formation of three disk
galaxies with a detailed treatment of chemical evolution and cooling. The
resulting galaxies have properties compatible with observations: relatively
high disk-to-total ratios, thin stellar disks and good agreement with the
Tully-Fisher and the luminosity-size relations. They present a break in the
luminosity profile at 3.0 +- 0.5 disk scale lengths, while showing an
exponential mass profile without any apparent breaks, in line with recent
observational results. Since the stellar mass profile is exponential, only
differences in the stellar populations can be the cause of the luminosity
break. Although we find a cutoff for the star formation rate imposed by a
density threshold in our star formation model, it does not coincide with the
luminosity break and is located at 4.3 +- 0.4 disk scale lengths, with star
formation going on between both radii. The color profiles and the age profiles
are "U-shaped", with the minimum for both profiles located approximately at the
break radius. The SFR to stellar mass ratio increases until the break,
explaining the coincidence of the break with the minimum of the age profile.
Beyond the break we find a steep decline in the gas density and, consequently,
a decline in the SFR and redder colors. We show that most stars (64-78%) in the
outer disk originate in the inner disk and afterwards migrate there. Such
stellar migrations are likely the main origin of the U-shaped age profile and,
therefore, of the luminosity break.Comment: 8 pages, 4 figures. Accepted by ApJ
Multi-wavelength spectroscopic study of shock-driven phenomena in explosive outbursts in symbiotic-like recurrent novae with an emphasis on RS Ophiuchi
Aims. Our goal is to detail the development of RS Ophiuchi and the other Galactic symbiotic-like recurrent novae throughout their outburst and quiescence, with a particular emphasis on the propagation of the shock wave during the outburst of the binaries. Methods. The spectral analysis has been performed using archival data according to the features of the individual datasets. Swift grism spectra were reduced and extracted using a combination of the pre-existing UVOTPY Python routine and newly written pipelines in Matlab. Other datasets were directly available in reduced form, already corrected for instrumental or background contamination, and calibrated in wavelength and flux or intensity. The work on these was done through pipelines suited for reading the data and elaborating them to extract quantities of interest for the analysis. Results. We find striking similarities in different outbursts of the same object and for different novae. For example, RS Oph 2021 was almost identical to the 2006 outburst, despite having occurred at a different orbital phase with the observations made from a different line of sight through the red giant wind. Despite the intrinsically different properties of the binaries, striking similarities are found for different systems of the same class, for instance, the trend of the electron density over time during outburst appears to follow a general temporal development
On the Schrodinger-Maxwell equations under the effect of a general nonlinear term
In this paper we prove the existence of a nontrivial solution to the
nonlinear Schrodinger-Maxwell equations in assuming on the nonlinearity
the general hypotheses introduced by Berestycki & Lions.Comment: 18 page
Low Energy Solutions for the Semiclassical Limit of Schrodinger–Maxwell Systems
We show that the number of positive solutions of Schrodinger– Maxwell system on a smooth bounded domain depends on the topological properties of the domain. In particular we consider the Lusternik– Schnirelmann category and the Poincaré polynomial of the domain
Nonlinear Klein-Gordon-Maxwell systems with Neumann boundary conditions on a Riemannian manifold with boundary
Let (M,g) be a smooth compact, n dimensional Riemannian manifold, n=3,4 with
smooth n-1 dimensional boundary. We search the positive solutions of the
singularly perturbed Klein Gordon Maxwell Proca system with homogeneous Neumann
boundary conditions or for the singularly perturbed Klein Gordon Maxwell system
with mixed Dirichlet Neumann homogeneous boundary conditions. We prove that
stable critical points of the mean curvature of the boundary generates
solutions when the perturbation parameter is sufficiently small.Comment: arXiv admin note: text overlap with arXiv:1410.884
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